Overuse of chemotherapy among younger patients with colon cancer, findings suggest

Colorectal cancer is the third leading cause of cancer death in the U.S. There were more than 49,000 deaths in 2016, and more than 134,000 new cases are expected this year. While incidence and mortality rates among adults age 50 and older have decreased recently in the U.S., the same trend hasn't been observed for patients 20 to 49. Treatment options remain to be defined for patients with young-onset colon cancer and their effects on prognosis are unclear.

Dr. Kangmin Zhu, professor in USU's Department of Preventive Medicine and Biostatistics, was corresponding author on the study, "Chemotherapy Use and Survival among Young and Middle-Aged Patients with Colon Cancer." He and his colleagues from the National Cancer Institute, and the John P. Murtha Cancer Center at USU (Department of Surgery) and the Walter Reed National Military Medical Center, examined whether there were age differences in receiving chemotherapy and whether there were matched survival gains with the receipt of postoperative chemotherapy among colon cancer patients. They analyzed data from the Department of Defense's Central Cancer Registry and Military Health System medical claims databases. There were 3,143 patients, ages 18 to 75, with histologically confirmed primary colon cancer diagnosed between 1998 and 2007.

Of these patients, 59 percent were men. Young (18-49 years) and middle-aged (50-64 years) patients were two to eight times more likely to receive postoperative systemic chemotherapy, compared with older patients (65-75 years), regardless of tumor stage at diagnosis. Young and middle-aged adults were 2.5 times more likely to receive multi-agent chemotherapy regimens. Also, while young and middle-aged adults who only underwent surgery had better survival compared with older patients, there were no significant differences in survival between young/middle-aged and older patients who received surgery plus postoperative systemic chemotherapy.

"Most of the young patients received post-operative systemic chemotherapy, including multi-agent regimens, not currently recommended for most patients with early-stage colon cancer. Our findings suggest young and middle-aged adults with colon cancer may be over-treated," Zhu said.